Although radiation has proven efficacy in the treatment of cancers that started in or spread to the liver, its usefulness is limited by the low dose that can be safely tolerated. The dose limiting side effect is referred to as Radiation Induced Liver Disease (RILD). This trial will assess the feasibility of whole liver radiation dose escalation utilizing a blood thinning agent (heparin) which may prevent the development of RILD, and alteplase (a blood clot dissolving agent) to reduce the severity of RILD should it occur. This strategy has been used to successfully to treat a similar toxicity which occurs following bone marrow transplant.